JPH0511703U - Electric vehicle travel control device - Google Patents

Abstract

(57) [Summary] (Corrected) [Purpose] In an electric vehicle, if the vehicle does not run even after starting operation, or if it stops during running, the cause is accurately displayed and repairs or other measures are promptly performed. To be able to do it. [Structure] A current value measuring means 2 for measuring a current value flowing through a drive motor 1 and a rotation speed measuring means 4 for measuring a rotation speed of the motor 1 are provided, and an electric signal output from both means 2, 4 is converted into a current value. On the basis of the result of the abnormality determination means 3 determining whether it is normal or abnormal and the rotation determination means 5 determining the presence or absence of rotation, it is displayed whether the drive system of the motor 1 is in failure or the rotation speed measuring means 4 is in failure, and the operation is stopped. I did it.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a travel control device for an electric vehicle that travels with the driving force of a motor.

[0002]

[Prior Art]

 The electric vehicle is provided with a rotation speed measuring means such as a tacho-generator for measuring the rotation speed of the drive motor to display the traveling speed and control the traveling speed. If this rotation speed measuring means fails or the signal line connecting the rotation speed measuring means and the control circuit is broken, it becomes impossible to control the running speed and sudden stop or runaway occurs. There is a fear. In order to prevent this, for example, in Japanese Unexamined Patent Publication No. 3-73146, at the start of traveling, the motor is reversely or normally rotated for a certain period of time to detect a change in the measurement output from the rotational speed measuring means, and if there is no change, disconnection occurs. It has been proposed to provide a disconnection detection means for determining that.

[0003]

[Problems to be solved by the device]

 In the signal line disconnection detection means connecting the rotation speed measurement means to the control circuit, the motor first reverses for a certain period of time when starting, so if the reverse rotation time is long, the vehicle body will retreat overnight and the riding comfort will be reduced. Not good, and sometimes dangerous on a slope. Further, when the driving force transmission path from the motor to the wheel is broken and locked, the motor does not rotate, so that there is no change in the measured output from the rotational speed measuring means and it is determined that the wire is broken. Therefore, it is an object of the present invention to accurately grasp the cause of failure when an electric vehicle does not run and to take appropriate measures.

[0004]

[Means for Solving the Problems]

 Current value abnormality determining means 3 for determining whether the current value measured by the current value measuring means 2 for measuring the current value of the wheel driving motor 1 is normal or abnormal, and rotation speed measurement for measuring the rotation speed of the motor 1. A rotation judging means 5 for judging the presence or absence of rotation based on the output from the means 4 is provided, and based on the judgment results of both judging means 3 and 5, a failure location is displayed and control such as traveling stop is performed.

[0005]

[Operation and effect of the device]

 When the current value abnormality determining means 3 determines that the current flowing through the motor 1 is abnormally high, the wheel drive system is locked for some reason and the motor 1 does not rotate, and when the vehicle runs up a steep slope. The case where the load of the motor 1 is increased, which case is clear by referring to the output of the rotation determination means 5. That is, the former is the case in which it is determined that it is not rotating, and the latter is the case in which it is determined that it is rotating even slightly. When the value measured by the current value measuring means 2 is zero, it is determined that the measuring means 2 itself is a failure or the signal line is broken.

Further, when the current value measured by the current value measuring means 2 is in a normal range, that is, when the motor 1 is rotating normally and the output from the rotation speed measuring means 4 becomes zero, the rotation speed measuring means 4 itself. Will be judged to be a failure or disconnection of the signal line. In this way, the state of the motor 1 is appropriately determined, so that in the case of an abnormality, control can be appropriately performed such that the motor 1 is immediately stopped or the motor 1 is rotated within a range that does not overheat. Further, by displaying whether the abnormality is the locked state of the motor 1 and its driving force transmission path, the failure of the rotational speed measuring means 4 or the disconnection of the signal line thereof, the repair can be performed quickly.

[0007]

【Example】

 Next, an embodiment of the present invention will be described with reference to the drawings. The electric vehicle shown in this embodiment is an electric wheelchair as shown in FIG. 4, in which a steering wheel shaft 7 for steering front wheels 6 is erected on the front part of a vehicle body 50 and a motor 1 for driving rear wheels 8 on the rear part. A prime mover 9 containing a battery is provided, and a seat 10 is provided above it.

A control operation unit 30 is provided on the upper portion of the steering handle shaft 7, and a high / low speed changeover switch 11, an accelerator lever 12, a horn switch 15 and the like are provided on the control operation unit 30, and a traveling speed and a battery A display unit 17 is provided to display the charging status and the failure position. The handlebars 13 projecting from the left and right sides are gripped to steer the front wheels 6 for steering operation.

The drive control circuit of the drive motor 1 for driving the rear wheels 8 is as shown in FIG. The arithmetic unit (CPU) 40 including the current value abnormality determination means 3 and the rotation determination means 5 in the present embodiment is connected to the ROM 14 in which the control conditions are stored, and inputs the movement of the accelerator lever 12 as the voltage change amount. The speed command means 2 is connected, and the running condition setting means 16 such as the high / low speed changeover switch 11 and the horn switch 15 are connected. Further, the arithmetic unit 40 is connected with a display means 17 for displaying the charging status of the battery, a failure position, etc., and a relay 31 for switching between forward and backward movements, and is connected to the motor drive circuit 18 so as to output drive conditions. There is.

The motor drive circuit 18 is connected to the drive motor 1 via transistors 19 and 20 and relays RL1 and RL2. Reference numeral 21 is a resistance for measuring the value of the current flowing to the drive motor 1 and constitutes the current value measuring means 2, and the current value is inputted to the arithmetic unit 40. A tachometer 22 corresponding to the rotation speed measuring means 4 is mounted on the rotation shaft of the drive motor 1, and the rotation signal is input to the arithmetic unit 40 to be converted into the rotation speed of the rear wheel 8 to calculate the actual traveling speed V. I am trying to do it.

Next, what kind of control signal is specifically sent from the arithmetic unit 40 to the motor drive circuit 18 will be described. When the accelerator lever 12 is set to the traveling state after switching to high speed or low speed running by the high / low speed changeover switch 11, the command speed Vs indicated by the degree of inclination of the accelerator lever 12 is read into the arithmetic unit 40, and the tacho generator 22. Under the condition that the rotation signal is read by the arithmetic unit 40 from the above and the actual speed V internally calculated is smaller than the command speed V s by 1 Km / h or more, the actual speed V is smaller than 1 Km / h, that is, at the time of start. After calculating the variable a by the following formula, the duty D is calculated by the formula and the motor drive circuit 18 is controlled to rotate the motor 1. a = 2000 + (1000-V) × 2 ──── D = D + (Vs-V) / a + 1 ──── After 25 ms, the command speed Vs and the actual speed V are read again and the calculation of the duty D is repeated. However, when the actual speed V becomes 1 km or more and a certain speed comes out, the variable a is set to 2000, and the duty D is calculated by the formula to control the rotation of the motor 3.

When the actual speed V approaches the command speed Vs and becomes a difference within 1 Km / h, the increasing rate of the duty D 1 is decreased and the constant speed control is performed. The motor drive circuit 18 controls the energization time to the motor 1 by the duty D, and the specific energization time is controlled as follows. One cycle of 25 ms time is divided into 250, and driving signals, braking signals, and neutral signals are arranged during that, and the duty D indicates the number of driving signals. When the command speed Vs is 6 Km / h, the actual value is obtained. The relationship between the speed V and the increase rate of the duty D is as shown in Table 1 below.

[0013]

[Table 1]

While the drive signal is being output, + 24V power is supplied to the motor 3, and the rotation speed increases in accordance with the supply time. Further, while the braking signal is being output, the motor 3 functions as a generator, and the generated electricity is returned to the motor 1 for dynamic braking.

The abnormality monitoring of the motor 1 and the tacho generator 22 is performed as shown in FIG. First, it is judged whether or not the current value I flowing through the motor 1 measured by the current value measuring means 2 exceeds the normal value range (for example, 25 A at maximum in the case of current limiting 30 A control). If the current value I is abnormally large, it is judged whether or not the rotation speed is detected by the rotation speed measuring means 4. If it is not rotating, it means that the motor 1 or the driving force transmission path is locked. , The display is performed and the power supply to the motor 1 is cut off and stopped. If it is spinning, it is determined that the vehicle is under heavy load, such as when it is climbing a slope, so it will continue to run while monitoring to prevent it from overheating.

If the current value I is within the normal range, the rotation speed measuring means 4 determines whether or not the motor 1 is rotating, and if it is determined that the motor 1 is not rotating, the rotation speed measuring means 4 is abnormal, Then, the display is displayed and the power supply to the motor 1 is cut off and stopped. If it is rotating, the motor 1 and the rotation speed measuring means 4 are operating normally, so that normal traveling control is performed.

[Brief description of drawings]

FIG. 1 is a flowchart of control.

FIG. 2 is a flowchart of control.

FIG. 3 is a control circuit diagram.

FIG. 4 is an overall perspective view of an electric vehicle.

FIG. 5 is a partial enlarged perspective view.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Wheel drive motor 2 Current value measuring means 3 Current value abnormality determining means 4 Rotation speed measuring means 5 Rotation determining means

Claims (1)

[Claims for utility model registration] [Claim 1] Current value abnormality determination for determining whether the current value measured by the current value measuring means (2) for measuring the current value of the wheel driving motor (1) is normal or abnormal Means (3) and rotation speed measuring means (4) for measuring the rotation speed of the motor (1)
Rotation determination means (5) for determining the presence or absence of rotation based on the output from
And a driving control device for an electric vehicle, in which a failure location is displayed on the basis of the determination results of both determination means (3) and (5) and control such as traveling stop is performed.